Field validation of the performance of paper-based tests for the detection of the Zika and chikungunya viruses in serum samplesby Margot Karlikow et al.
In low-resource settings, resilience to infectious disease outbreaks can be hindered by limited access to diagnostic tests. Here we report the results of double-blinded studies of the performance of paper-based diagnostic tests for the Zika and chikungunya viruses in a field setting in Latin America. The tests involved a cell-free expression system relying on isothermal amplification and toehold-switch reactions, a purpose-built portable reader and onboard software for computer vision-enabled image analysis. In patients suspected of infection, the accuracies and sensitivities of the tests for the Zika and chikungunya viruses were, respectively, 98.5% (95% confidence interval, 96.2–99.6%, 268 serum samples) and 98.5% (95% confidence interval, 91.7–100%, 65 serum samples) and approximately 2 aM and 5 fM (both concentrations are within clinically relevant ranges). The analytical specificities and sensitivities of the tests for cultured samples of the viruses were equivalent to those of the real-time quantitative PCR. Cell-free synthetic biology tools and companion hardware can provide de-centralized, high-capacity and low-cost diagnostics for use in low-resource settings.
*Portuguese content* Com objetivo de avaliar como as famílias dessas crianças foram impactadas, a pesquisa Impactos econômicos e sociais do vírus Zika foi realizada no IFF-Fiocruz, hospital público federal situado no Rio de Janeiro, que atua em ensino, pesquisa e atendimento a mulheres, crianças e adolescentes.
In 2015–2016 in the Recife Metropolitan Region, the authors of this study detected the tail end of a Zika epidemic, which was displaced by a chikungunya epidemic. Few dengue cases were identified despite a high number of official dengue notifications in the area during this period. This study shows here important epidemiological features of these cases.